Infectious Disease

Front 1

1. A high percentage of infants born in hospital maternity units have anterior nares colonized by S. aureus. True/False

Back 1

True. The baby's colon is usually colonized within 6-12 hours. If breastfed this is mainly with bifidobacteria, and bottle fed, mainly with Enterobacteriaceae.

Front 2

2. What is Blind Loop syndrome?

Back 2

This is an adverse effect of the indigenous human flora. It is an overgrowth of bacterial intestinal contents in blind ending loop left after surgical procedure.

Hepatic encephalopathy- gut derived bacterial toxins that are no longer removed from the portal circulation when the liver begins to fail.

Front 3

3. Leukocidin is a staphylococcal toxin. True/False

Back 3

True. Some species produce mucolytic enzymes to penetrate the mucus layer on internal body surfaces. Others have specific adhesins to enable binding receptor site on cells(gonococcal pili attachment to urethral epithelium, and influenza virus adherence to glycoprotein receptors on upper respiratory mucosal cells.

Front 4

4. List 3 organisms that can inactivate IgA globulins.

Back 4

1. Haemophilus influenzae

2. Strep. pneumoniae

3. Neisseria meningitidis

Front 5

5. Some parasites(schistosomes), the cause of bilharzia, can penetrate intact skin. True/False

Back 5

True.

Front 6

6. what are droplet nuclei?

Back 6

Potentially infective particles known as droplet nuclei are less than 5um diameter and many reach the alveoli where they can establish an infection.

Front 7

7. what are the effects of cytotoxins?

Back 7

In the GI tract some disease causing organisms damage the mucosal surface by releasing cytotoxins(dysentery), while others like Salmonella typhiiare taken up by M cells overlying gut associated lymphoid tissue(GALT) in Peyer's patches.

Front 8

8. List some organisms that can cause a placental infection in the mother during pregnancy.

Back 8

The fetus is not normally exposed to micro-organisms in utero. Intrauterine infections may be caused by toxoplasmosis, rubella ,syphilis and cytomegalovirus.

Front 9

9. In bacteria, toxins are usually of a protein nature. True/false

Back 9

True. The organism usually releases these, or a lipopolysaccharide complex in the cell wall and liberated during cell growth or lysis. These are:

tetanospasm

botulinum toxin

cholera toxin

diptheria toxin

Front 10

10. Many exotoxins have 2 principle subunits. What are they?

Back 10

A(active) and B(binding). The B unit determines tissue specificity, while the A subunit causes cellular damage after binding by B and penetration of the cell membrane.

Front 11

11. Microorganisms compete for substrates and growth limiting factors such as iron and other elements. True/False

Back 11

True. Many have defenses against phagocytic cells, polysaccharide capsule of S. pneumoniae, antiphagocytic toxin such as Staphylococcal leukocidin, and even a capacity to survive inside macrophgaes, as in M. turberculosis.

Front 12

12. The genetic control of microbial virulence is complex. T/F

Back 12

True. In bacteria, the gene coding for toxin production may be on the chromosome, plasmids or even in a bacteriophage.

Front 13

13. The products of the structural genes have been classified in a series of categories. What are they?

Back 13

Adhesins, Invasins, and Toxins, cloaking, shielding and scavenging factors. According to the environment, the virulence factor may be switched on or off. It is clear that the genes responsible for virulence are in coregulated groups known as pathogenicity islands.

Front 14

14. How do antibiotics based on beta lactams function?

Back 14

They interfere with Muramic acid polymerisation by inhibiting the transpeptidase that forms the final cross links between N-acetyl muramic acid and N acetyl-glucosamine. The lack of intact murein renders the bacterial cell susceptible to osmotic lysis. The two main groups are penicillins and cephalosporins.

Front 15

15. The polymixins act like a detergent and disrupt the membrane causing leakage of cytoplasmic contents. True/False

Back 15

True. Fungal cell membranes have sterols particularly ergosterol. The polyenes(amphotericin bind sterol containing membranes causing them to leak. The imidazoles prevent ergosterol synthesis, resulting in membrane disruption.

Front 16

16. How does the bacterial ribosome differ from ribosomes in mammalian cells?

Back 16

They have 30s and 50s subunits.

Front 17

17. How do macrolides work?

Back 17

Ex, Erythromycin binds to the 50s subunit of ribosomal RNA and half the formation of initiation complexes.

Chloramphenicol binds the 50S subunit and interferes with the linking of amino acids in the growing peptide chain.

Front 18

18. How do tetracyclines function?

Back 18

They bind to the 30s subunit and prevent the binding of transfer RNA, which halts amino acid chain elongation.

Front 19

19. A number of antimicrobial agents act on the microbial genome. List several of them.

Back 19

1.Quinolones

2. Sulphanamides

3. Diaminopyrimadines

4. Rifamycins

5. Nitroimidazoles.

Front 20

20. What is the basic mechanism of action of Sulphanamides?

Back 20

These represent false substrates for folate synthesis, which bacteria require for purine and thymydilic acid synthesis. Trimethoprim(diaminopyrimidines) also act on folate synthesis in the metabolic pathway.

Front 21

21. How do Rifamycins work?

Back 21

Rifampicin prevents transcription by inhibiting DNA dependent RNA polymerase.

Front 22

22. How do Nitroimidazoles work?

Back 22

Metronidazole acts only after nitro-reductases active at low redox potential, metabolize them to active intermediates that cause DNA strand breakages.

Front 23

23. How do the Quinolone antibacterials work?

Back 23

The Quinolones(ciprofloxacin) act by preventing the action of DNA gyrases, enzymes, bacteria use to produce super-coiling, nicking and resealing of DNA during replication.

Front 24

24. Viral replication occurs much more rapidly than replication in the mammalian cell, accounting for the vulnerability of this process to antiviral agents. True/False

Back 24

True. The most commonly used agents are nucleotide analogues that cause chain termination during transcription(acycloguanosine,zidovudine, flucytosine, idoxuridine). (ZAFI)

Acycloguanosine, inhibits viral DNA polymerase only after a final phosphorylation step by viral thymidine.

Front 25

25. How does Griseofulvin work?

Back 25

It interferes with formation of the mitotic spindle.

Front 26

26. How do the arsenicals and antimonials used in the treatment of parasitic infections work?

Back 26

They interfere with glucose metabolism, and quinine inhibits the heme polymerase required to prevent poisoning of the malarial parasite by monomeric hemoglobin.

Front 27

27. Sulphanamides in children have been known to cause jaundice. True/False

Back 27

True.

Front 28

28. Define minimum inhibitory concentration.

Back 28

The lowest concentration at which organisms do not produce visible growth.

Antibiotic test discs is another method employed.

Front 29

29. what is minimum bactericidal level?

Back 29

The lowest concentration at which bacterial growth does not occur is called minimum bactericidal level. If there is a wide margin between MIC and MBC, the organism is said to be tolerant of the antimicrobial agent in question.

Front 30

30. of the antibacterial agents in common use, aminoglycosides and glycopeptides have the lowest threshold of toxicity. True/False

Back 30

True.

Front 31

31. Around 10% of patients with allergy to penicillins, also have an allergy to cephalosporins. True/False

Back 31

True. Rarely, administration of gradual doses of the agent may desensitise individuals.

Front 32

32. Repeated antibiotic therapy is a common cause of Thrush or Candidiasis, caused by an overgrowth of Canadida albicans. True/false

Back 32

True.

Front 33

33. What is meant by intrinsic resistance?

Back 33

This is when the organism lacks the target site for the agent or has other features that always render it resistant to the agent.

Front 34

34. What is phenotypic resistance?/

Back 34

This is not genetically determined. There are two types.

L form bacteria- which lack a cell wall but survive in an iso-osmolar environment despite continued exposure to antibiotics.

Genotypic resistance is determined genetically by resistance factors carried in the chromosome or on extrachromosomal genetic material called plasmids.

Plasmids can replicate independently of the bacterial chromosome.

Front 35

35. What are the four principle mechanisms of acquired resistance?

Back 35

1. Enzyme mediated

2. Altered target site

3. Altered transport

4. Altered metabolic pathway

Front 36

36. Enzymes have been described that inactivate the beta lactam agents, aminoglycosides and chloramphenicol. True/False

Back 36

True. These are beta lactamases and hydrolyze the beta lactam ring.

In G+ bacteria, beta lactamases are released into the surrounding medium, but G- bacteria tend to produce smaller quantities in the periplasmic space, where there are high concentrations.

Front 37

37. The presence of porins in the outer cell wall of G- bacteria assures that small amounts of beta lactam agents reach the periplasmic space and the waiting B lactamase. True/False

Back 37

True. They can be chromosomal or plasmid in origin.

Front 38

38. What are the three groups of enzymes that inactivate aminoglycosides?

Back 38

1. Acetyl transferases

2. Adenyl transferases

3. Nucleotidyl transferases

These are plasmid mediated and and found in G- bacilli.

Acetyl transferase can inactivate chloramphenicol.

Front 39

39. Give an example of altered site resistance.

Back 39

Examples include changes in the penicillin binding proteins of S. aureus which confer resistance to a range of beta lactam agents including methicillin(MRSA).

Front 40

40. Chromosomal resistance to the quinolone agents(ciprofloxacin) can can be caused by production of a mutant DNA gyrase. True/False

Back 40

True.

Front 41

41In some species, tetracycline resistance is caused by increased active transport out of the organism(pump ejectors). True/False

Back 41

True.

Front 42

42. Antimicrobial agents that act on metabolic pathways are prone to resistance developing as a result of mutations favoring alternative pathways. true/false

Back 42

True. An example is trimethoprim.

Front 43

43. List 4 types of gene transfer between bacteria.

Back 43

1. Conjugation

2. Transduction

3. transformation

4. Transposition.

Front 44

44. Define conjugation.

Back 44

This involves the transfer of plasmid DNA(extrachromasomal) circular DNA fragment, from one bacterial cell to another via a hollow pilus and subsequent incorporation in the recipient genome.

Front 45

45. Define Transduction.

Back 45

This relies on a bacteriophage to act as a vector of DNA transfer between bacterial cells.

Front 46

46. Define Transformation.

Back 46

This occurs when fragments of chromosomal DNA are released during bacterial cell lysis and taken up across the intact cell wall of a recipient bacterial cell.

Front 47

47. Define Transposition.

Back 47

This occurs when a transposon leaves one site in the bacterial genome and inserts into another site in the bacterial genome.

Front 48

48. Why is Acquired antimicrobial resistance so widespread?

Back 48

This is due to the bacteria's ability to transfer resistance factors between strains and species, with subsequent spread between patients in hospitals.

Front 49

49. Define Transposon.

Back 49

These are sequences of genes that have the ability to recombine with both the chromosome and any plasmid.

Front 50

50. What is meant by "Patent regulation" in the pharmaceutical industry?

Back 50

This means that they have to achieve a return on their investment within 15 years.

Front 51

51. vaccines such as the Sabin polio vaccine use live virus to provoke a protective immune reaction. True/False

Back 51

True.

Front 52

52. Is hepatitis B vaccine a subunit vaccine?

Back 52

Yes. It has been possible to genetically engineer components that stimulate protective immunity without causing disease.

Front 53

53. What is Chlorhexidine?

Back 53

It is a diphenyl disinfectant, activeagainst a wide range of microorganisms.

Front 54

54. What is Povidon iodine?

Back 54

It is an iodophor compound, it releases active iodine, a potent antimicrobial agent. It is less allergenic than liquid iodine.

Front 55

55. What are Aldehyde compounds effective against?

Back 55

They are effective against all bacteria, fungi, viruses and bacterial spores. they are too toxic to directly use on tissues. They are used to decontaminate equipment(glutaryldehyde solution, or formaldehyde vapour.

Front 56

56. Phenolic disinfectants are too toxic to use on tissues. True/False

Back 56

True.

Front 57

57. what is required in Pasteurization?

Back 57

This requires heating the fluid to a temperature below 100C at which vegetative bacteria can be killed. The duration of heating depends on the temperature used: 63C for 30 minutes, or 71 for 30 seconds.

Front 58

58. Autoclave cycles with a higher sustained temperature of 134C are employed to disable possible prion contamination. True/False

Back 58

True.

Front 59

59. what is Folliculitis?

Back 59

Papules due to focal infection of hair follicles.( Staph. aureus)

Furuncle-Acute, focal pyogenic infection in the skin , appearing as an angry pustule or lump.

Carbuncle- Confluence of several skin abscesses with multiple drainage points.

Paronychia-nail fold infection when hands are frequently immersed in water.

Onychia- Nail bed infection causing, distortion/discoloring of the nail.

Acne- Vesiculo pustular infection of the sebaceous glands in teenagers and young adults.(Proprionibacterium acnes)

Front 60

60. what causes paronychia?

Back 60

S. aureus, Gram negative bacilli, Candida species, and herpes simplex.

Front 61

61. what are some features of Actinomycosis?

Back 61

Penetrative suppurative lesions with purulent exudate, sinus tracts and yellow flecks.

Front 62

62. Occasionally, Sporothrix schenckii can cause chronic lymphangitis. True/False

Back 62

True. Nematodes such as Wucheria bancrofti and Brugia malayi often cause it as well.

Front 63

63. Sporotrichosis follows minor trauma caused by plants(rose thorn and results in a string of subcutaneous nodules corresponding to the lymphatic vessels. True/False

Back 63

True. Tx is with potassium iodide solution or itraconazole.

Front 64

64. C. tetani produces a toxin called tetanospasmin in the anerobic conditions. True/False

Back 64

True. The toxin is taken up by motor neurones and blocks the action of presynaptic inhibitory neurotransmitters, including glycine and Y-amino butyric acid(GABA), resulting in an exaggerated motor response.

Front 65

65. Necrotizing fascitis is usually caused by S. pyogenes( group A, B- hemolytic streptococci. True/False

Back 65

True. Surgical exposure of the affected fascial planes and deep incision to expose the fascia is often required. Clindamycin has been used for its broad tissue availability.

Front 66

66. what is the bacterial agent of leprosy?

Back 66

Mycobacterium leprae. Three overlapping intermediate stages are recognized, BT, BB and BL.

TT: asymmetric nodules, hypopigmentation, anesthesia of adjacent nerve thickening, lepromin test positive.

LL form: Symmetrical macules, extensive skin involvement, enlarged earlobes, and facial tissues nasal discharge, lepromin test negative.

Skin scrape or biopsy followed by acid fast stain for mycobacteria.

Front 67

67. What is the treatment for Leprosy?

Back 67

Dapsone, a long acting sulphanamide, with rifampicin.

All types of leprosy require clofazimine with the exception of TT form.

Front 68

68. What is Erysipeloid?

Back 68

A lesion that looks like erysipelas, a red raised plaque like patch of inflammed skin with a definite edge, but it is caused by a different bacterial species to erysipelas.

It often occurs on the hands of butchers and fishery workers.

Erysipelothrix rhusiopathiae, a non spore forming G+ bacillus causes the condition.

treated with penicillin though it can be self limiting.

Front 69

69. What is Fish tank granuloma?

Back 69

A suppurative or granulomatous skin lesion that occurs following minor trauma in fish tanks or swimming pools. Its cause is Mycobacterium marinum.

Front 70

70. What is Orf?

Back 70

This is the result of a poxvirus that infects farm workers during close contact with lambs. This condition tends to resolve spontaneously.

Front 71

71. what is cutaneous diptheria?

Back 71

A chronic skin ulcer with a dirty grey membranous base. It is usually seen in tropical climates. it is caused by C. diptheriae. S. aureus and group A strep are secondary invaders. There is no response to antitoxin therapy.

Front 72

72. give a brief description of Cutaneous leishmaniasis.

Back 72

This is a cutaneous parasitic infection caused by the protozoa Leishmania. They are transmitted by sandflies.

Front 73

73. What are some antimicrobial factors present in respiratory secretions?

Back 73

Lysozyme, lactoferrin and secretory IgA. Particles in the size range of 5-10um may penetrate further into the lungs and potentially reach the alveoli.

Front 74

74. regarding enzymes, what do S. pneumoniae and H. influenza have in common?

Back 74

They both produce an enzyme capable of disabling mucosal IgA, IgA protease. These two species, other capsulated bacteria and mycobacteria are all resistant to phagocytosis.

Front 75

75. Vaccination with a live attenuated strain (BCG) can prevent infectionwith M. tuberculosis infection. True/False

Back 75

True. Protection against pulmonary infection however, is partial.

Front 76

76. What are some viral causes of pharyngitis?

Back 76

Rhinovirus

Coronavirus

Adenovirus

Influenza virus

Parainfluenza

Respiratory syncytial virus

Epstein-Barr virus

Coxsackie virus

Front 77

77. bacterial pharyngitis is less common and its single most frequent cause is S. pyogenes. True/False

Back 77

True. Other less common causes include Neisseria gonorrhea, mycoplasma pneumoniae, Corynebacterium diptheriae and Arcanobacterium hemolyticum.

Front 78

78. What tests could be run to confirm Epstein Barr virus?

Back 78

Paul Bunnel test for heterophile antibodies and full blood count. This is however, not sensitive in Asians. Here one should seek IgM to viral capsid antigen.

Front 79

79. Which organism is most found in pharyngitis?

Back 79

Detection od S. pyogenes. Blood agar culture, latex agglutination reaction for group specific polysaccharide or by direct antigen detection.

Front 80

80. what is a logical treatmrent of S. pyogenes?

Back 80

Penicillin V or erythromycin. Though resistance is becoming a problem, the treatment may not alter the course of the primary pharyngeal infection, but could reduce the risk of non infective sequelae such as Rheumatic heart disease, post strep glomerulonephritis and Sydenham's chorea.

Front 81

81. What is Sydenham's chorea?

Back 81

Sydenham's chorea or chorea minor (historically referred to as Saint Vitus Dance) is a disorder characterized by rapid, uncoordinated jerking movements primarily affecting the face, hands and feet.[1] Sydenham's chorea (SC) results from childhood infection with Group A beta-haemolytic Streptococcus[2] and is reported to occur in 20–30% of patients with acute rheumatic fever (ARF).

Front 82

82. Epidemic and endemic influenza occurs usually by type A. True/False

Back 82

True. Though similar to a cold, fever is almost always present with the flu.

It is an RNA virus with a segmented genome. Two major antigens in typing epidemic strains are hemagglutinin and neuraminidase. genetic reassortment is responsible for the different types of flu.

Front 83

83. Why does antigenic shift result in influenza epidemics?

Back 83

It renders preexisting specific immunity to influenza virus antigens obsolete.

Front 84

84. In otitis media purulent fluid accumulates behind a tense, red tympanic membrane. True/False

Back 84

True. It may discharge externally after rupture of the membrane. S. pneumoniae and H. influenzae is often the cause of the infection, while fever and pain are local features.

Complications include mastoiditis and meningitis, though these conditions are rare.

Front 85

85. What is otitis externa?

Back 85

It is inflammation of the external auditory meatus. This is often the result of the hyphae forming fungus aspergillus niger.

A malignant otitis externa can occur in diabetics and is often caused by Pseudomonas aeruginosa. Appropriate anti pseudomonas therapy is indicated.

Front 86

86. When does acute Rhinosinusitis occur?

Back 86

This occurs when the sinus ostia become obstructed as a result of viral infection or allergen stimulation. These are usually self limiting.

Strep. pneumoniae and H. influenzae are usually involved.

Front 87

87. Acute bronchitis usually involves a cough, and sputum production. True/False

Back 87

True. Mycoplasma pneumoniae is often the cause.

Front 88

88. Legionella and Mycoplasmas can be cultured. True/False

Back 88

True. There is however, a low detection rate when compared with molecular(PCR) methods.

Front 89

89. Pneumococcal pneumonia can be prevented by vaccinating with a polyvalent vaccine to capsular polysaccharides. True/False

Back 89

True. protection is partial because of changes that occur in the relative prevalence of particular pneumococcal capsular types(84 at present).

Front 90

90. What is the most common cause of nosocomial pneumonia?

Back 90

Pseudomonas aeruginosa, S. aureus and the Enterobacteriaceae. Legionella and some respiratory viruses are responsible less frequently.

Front 91

91. primary infection with tbc follows airborne transmission from a case of pulmonary tbc. True/False

Back 91

True.Exposure results in formation of a thick primary complex. The thick lipid containing cell wall of mycobacteria renders the organisms resistant to phagocytosis. Fibrosis then walls off the inhaled bacteria to form a granuloma with central caseating necrosis.

Front 92

92. What is an effective treatmnet regimen for tbc?

Back 92

Combination therapies considered are Rifampicin, Isoniazid, Ethambutol and Pyrazinamide.

Front 93

93. Is there a prevetive approach for tbc?

Back 93

In some countries, it is by intradermal inoculation of a live attenuated srain of mycobacterium(bacillus-Calmette-Guerain; BCG) after tuberculin skin testing or quantiferon test has demonstrated non reactivity.

Front 94

94. What is Tropical Sprue?

Back 94

This is a malabsorption syndrome affecting adults who have reided or visited tropical countries. Its cause is unknown, but has responded to tetracycline. Some may resolve spontaneously.

Front 95

95. What is Diphyllobothrium latum?

Back 95

This is a fish tapeworm found in fresh water lakes.

Cysts are ingested and the tapeworm is established in the small intestine where it can cause a B12 deficiency and macrocytic anemia. Stool microscopy is diagnostic, and it is treated with mebendazole.

Front 96

96. What infectious agents have been found in proctitis?

Back 96

Shigella, entoamoeba as well as sexually transmitted diseases.

Front 97

97. What are some organisms that cause hepatitis?

Back 97

Hep. viruses A-E, cytomegalovirus, various arboviruses and Leptospira icterohemorrhagica. The jaundice these cause are related to hepatocellular damage. The jaundice this causes results in raised unconjugated bilirubin in blood and urine(urine may not be darker than usual).

Front 98

98. Hep. A is spread via the fecal oral route. True/false

Back 98

True. It is an enterovirus with an incubation period of 2-6 weeks. Dark urine and pale stools provide evidence of cholestatic jaundice.

The patient is infectious for 2-3 weeks. Immunity is usually lifelong.

Front 99

99. How is Hep. A. diagnosed?

Back 99

It is by detection of a rising antibody titer(ELISA) or demonstration of anti-HVA IgM in the serum.

Specific treatmrnts are of little value, and alcohol should be avoided for 1 year. A vaccine is available.

Front 100

100. Hep. B. is spread via blood products and fluids. True/False

Back 100

True. Hep. B surface antigen is a marker for disease but fails to distinguish active hepatitis afetr 6 weeks from the time of infection.

The few cases that remain HBsAg positive after 6 months are considered carriers.

Hep. B. e antigen is a good marker for high level infectivity.

Front 101

101. In Hep. B, antibodies to the surface antigen are protective against further infection and do not appear in significant titerin patients with chronic active disease. True/False

Back 101

True. Anti-core antibodies are used to confirm recent hepatitis B infection when all other tests are negative. Vaccination is available.(deltoid muscle).

Self needle jabbing by accident is a common possible risk for the disease. (Resheathing of needles).

Front 102

102. Hepatitis C used to be called non A and B hepatitis. True/False

Back 102

True. It was distinct from both A and B. Hep. C appears to be more common than hep. B.

Front 103

103. Is there a treatment for Hep. C?

Back 103

At one time, and is still employed, treatment was with pegylated interferon alpha plus ribavirin.The specific genotype of the virus decides the specific treatment.

Though encouraging, the new Hep.C drug Harvoni is still considered experimental. Its cost is controversial.

Front 104

104. Hepatitis D was previously called the delta agent. True/False

Back 104

True. It does not cause hepatitis on its own. It acts with Hep. B. to cause a severe co-infection.

It is a defective RNA virus that cannot replicate in the absence of Hep. B. virus. This virus is known to infect I/V drug abusers.

Front 105

105. How is Hep. E. virus spread?

Back 105

It is believed spread via the fecal oral route.

Front 106

106. List 2 Arboviruses that can cause jaundice.

Back 106

Yellow fever and Haantavirus.

Front 107

107. Can Leptospirosis cause a hepatitis like clinical picture?

Back 107

Yes. Spirochete bacteria(genus, Leptospira) cause the infection. There can be petecchiae and renal failure. Jaundice is not uncommon in this disease.

Front 108

108. can liver abscesses be caused by Entamoeba histolytica?

Back 108

Yes. This can occur after an ascending pyogenic infection, especially in the biliary tract or GI infection.

The bacterial species isolated from pyogenic liver abscesses include anerobic bacteria, Enterobacteriaceae or Streptococcus angionosis-constellatus.

Front 109

109. What is Cholecystitis?

Back 109

This is an inflammation of the gall bladder. This often occurs in women over 50 years of age. There is pain, fever, rigors, abdominal pain and subcostal tenderness of the right hand side. gall stones are a frequent cause.

Front 110

110. what is Charcot' triad?

Back 110

Obstruction of the biliary tract cauased by infection or cholangitis. Sometimes this may be secondary to an obstruction of the common bile duct with a gall stone or tumor(cvholangiocarcinoma, pancreatic carcinoma. The clinical features are jaundice, fever and chills. (Charcot triad)

Front 111

111. Acute pancreatitis is often the cause of severe, sudden onset abdominal pain accompanied by shock. True/False

Back 111

True. Obstruction of the pancreatic duct by gallstones, excessive alcohol and Mumps virus infection in adults.

Front 112

112. many laboratories use borate crystals as a preservative for urine specimen. True/False

Back 112

True.

Significant pyuria is said to be present when there are more than 10(8) cells/ml of urine. This is an active UTI.

Front 113

113, For treatment of UTI, there are several agents used for treatment of uncomplicated lower UTI. True/False

Back 113

True. These include nitrofurantoin, Nalidixic acid and Trimethoprim. None of these are suitable in early pregnancy, where we should use a Beta lactam such as ampicillin or a cephalosporin instead. Ampicillin resistance is common.

Front 114

114. Cystitis is more common in females than males throughout life. True/False

Back 114

True. E. coli is a very commonly found organism. other species found are Staph. saprophyticus, other enterobacteriacae and less commonly S. aureus and C. albicans(often associated with diabetes. Mnay aof these agents have a strong adhesion to bladder epithelial cells.

Front 115

115. The species commonly isolated in pyelonephritis are E. coli, other Enterobacteriaceae and S. aureus. True/False

Back 115

True.

Front 116

116. what are some host factors that contribute to the pathogenesis of pyelonephritis?

Back 116

These include indwelling urinary catheter, neurological diseases, renal stones, ureteric reflux and pregnancy. Bacterial factors implicated in pathogenesis include P-pili.

Front 117

117. What is Perinephric abscess?

Back 117

This is a collection of pus located underneath the renal capsule, but external to the renal medulla.

Front 118

118. Which organisms can cause Prostatitis?

Back 118

These might be the same organisms that cause lower UTI-E.Coli, Enterococcus fecalis, S. aureus and occasionally Corynebacterium.

Front 119

119. List two A/Bs that achieve good levels in the prostate?

Back 119

Trimethoprim and Ciprofloxacin.

Front 120

120. Neisseria gonorrhaea became resistant to the sulphonamides not long after their introduction. True/False

Back 120

True.

Front 121

121. Herpes simplex virus infects squamous epithelial cells and forms an intranuclear inclusion body. True/False

Back 121

True.

Front 122

122. Viral DNA from HPV 16 and 18 has been demionstrated in cancerous cervical tissue. True/False

Back 122

True. It is believed that malignant transformation is caused by deregulation of epithelial cell DNA following viral integration.

Not all 57 types are associated with cervical dysplasia intraepithelial carcinoma or overt malignancy.

Front 123

123. What has been a control protocol for genital warts?

Back 123

The painting of podophyllin on the lesions as a local cytotoxic agent once weekly for 5 weeks. This is however, less effective than trichloroacetic acid solution. Cryotherapy and electrocautery is used in stubborn cases.

Front 124

124. What is the causal agent of Syphilis?

Back 124

Treponema pallidum. It is found in the chancre during its appearance.

Chancres heal spontaneously, and at this time lesions of secondary syphilis appear.

Front 125

125. How does syphilis appear after secondary syphilis has become evident?

Back 125

The disease becomes latent until years to decades later when late manifestations(gummas or neurosyphilis), referred to as tertiary syphilis occur in about 25% of untreated patients.

Front 126

126. Can T. pallidum be grown in the laboratory?

Back 126

No.

Front 127

127. What is the treatment for early syphilis?

Back 127

It is with an intramuscular dose of benzathine penicillin, or alternatively, with tetracycline or erythromycin.

Front 128

128. What is chancroid?

Back 128

This is an ulcerative condition of the external genitalia caused by Haemophilus ducreyi infection.

Front 129

129. How is H. ducreyi diagnosed?

Back 129

Gram stain and culture of the exudate from the ulcer starts the diagnosis. The appearance of H. ducreyi is chains of G- bacilli(streptobacilli) which have been described as schools of fish. Incubation in 5% CO2 at 33-34C is recommended.

Front 130

130. What is the treatment of H. ducreyi?

Back 130

Erythromycin, Trimethoprim, Ciprofloxacin and single dose Ceftriaxone can be employed.

Front 131

131. What is Lymphgranuloma venereum?

Back 131

It is a genital infection in which lymphadenopathy is the predominant feature caused by Chlamydia trachomatis.

Tx- Erythromycin or a sulphanamide. Vaccines are not available.